Molecular Breast Imaging to Guide Early-Stage Patient Care Molecular Breast Imaging (MBI) will one day provide decision guidance for patient management without the need to perform a biopsy - that is without the need to cut out tissue that often is found to be normal. MBI's future benefit to women's health will obviate stressful watching and waiting periods of months, and will guide chemotherapy or surgery decisions toward optimized outcomes. A suspicious growth is often seen in conventional mammography by casting its shadow on film. However, often the shadow becomes inconspicuous in the background of dense but normal tissues. MBI forms images through a completely different process: drugs of trace amounts are taken up in the abnormal tissues, and then shine gamma-rays out to an imaging instrument located near the breast. These imaging drugs, also known as "biomarkers", can be selected to probe specific biological processes of immediate concern to the physician. For example, the aggressiveness or invasiveness of a tumor can be probed by a biomarker designed to specifically target cellular proliferation (i.e., the rate of cell division and tissue growth). Other biomarkers can "light up" tumors featuring specified hormone receptors or other identifying cellular features known to be associated with certain types of cancer. One of these processes, namely the metabolic rate of proliferative cellular functions, is probed by the imaging agent known as 99mTc-sestamibi ("MIBI" for short). This agent was associated with breast cancer in the 1990s through the use of an imaging instrument known as the "Anger camera". This device, which was designed in 1957, has flexible utility in imaging any organ (from prostate to brain) as well as whole bodies. Only in recent years has the Anger camera been specially designed for imaging of an organ, namely the heart. The current proposal describes another specially designed camera, the Molecular Breast Imager, which forms images using a new, dual-head solid state detector that is a distinct improvement over the 52-year old Anger method. This detector has been developed by the applicant institution, Gamma Medica- Ideas (GM-I, Northridge, CA) in collaboration with researchers at the Mayo Clinic. Clinical trials conducted by Dr. O'Connor of the Mayo Clinic (one of the investigators on this project) demonstrate results that are superior to mammography for women with dense breasts - i.e., those women in whom shadows are difficult to cast. Dr. O'Connor also has shown MBI to be very specific, that is, resulting in few "false positives" that would lead to worrisome yet normal biopsy. The current proposal describes a program run by Gamma Medica-Ideas and involving clinical research collaborations at the Mayo Clinic, Cedars-Sinai Medical Center, and Harbor-UCLA. The aims are to commercialize the dual-head MBI scanner, to strengthen the case for routine use of MIBI for well-defined populations of women, and to associate new biomarkers with patients and disease stage such that subsequent decisions are non-invasively guided by MBI results. PUBLIC HEALTH RELEVANCE: Molecular Breast Imaging to Guide Early-Stage Patient Care Non-invasive molecular imaging promises to benefit breast cancer patient care while reducing costs and uncertainties. This will be achieved by the screening of selected, at-risk populations of women and providing definitive diagnosis and therapy guidance. We propose a commercialization program for a highly accurate instrument capable of imaging molecular imaging agents at the earliest, most treatable stage of breast cancer, thereby optimizing decision making toward improved and cost-effective outcomes